As a result of the bombing of Hawaii on Dec. 7, 1941 the opportunity was given to study and operate on a large number of patients with neurosurgical injuries.1This communication is a report of experience in the treatment of penetrating wounds of the head as seen among the first American casualties of the present war. Nearly all these wounds were compound depressed fractures of the skull produced by fragments of shrapnel which varied in size from thin flat pieces less than 1 cm. across (fig. 3) to large, heavy, irregular chunks of steel 3.5 to 4 cm. wide and 0.5 to 1 cm. in thickness ( fig. 1). The larger pieces of metal all had extremely sharp, jagged points, which ripped great irregular holes in the tissues of the head through which they passed. There were no round smooth bullets found in the group of patients treated. The nature